three kinds of ‘bet’ are – bet, bet, and bet.
Therefore, the proper answer would be an option – ‘c’.
Why the opposite options are wrong?
Well, allow us to scrutinize them to know why.
Option a contains the word – beat, it's the straightforward tense for the word beat and therefore the perfect participle tense for this word is – beaten. Therefore, this can be not the right option.
Option b contains the word beaten, as I told you earlier it's the perfect participle tense for the verb beat, that's why we cannot choose it.

Option c contains the word bet, and that we have stated earlier that it's the proper answer. And
Option d contains the word betted, this is often considered because the tense of the word bet. Therefore, this feature is additionally invalid to us as an accurate solution.
Therefore, ‘c’ is our answer/ solution for the above question.
We can also consider an example to grasp how the word ‘bet’ is employed. For e.g. - he had a game the winning team and he won k rupees.


Note: Be very clear with the principles regarding verbs before attempting the question. That way you'll not get confused between two different and plausible answers.